The invention relates to a device for the continuous application of self-adhesive handles to moving articles.
Conventional devices are mounted on a frame and include: means for supporting a spool of adhesive tape on one face, means for guiding the tape to a handle application station, a station that applies a section of non-adhesive tape or a label to the adhesive surface of the tape to form the gripping area of each handle with regular spacing, and at the application station, a paddle rotating about a horizontal, transverse axis that is disposed above the trajectory of the articles moving on a conveyor belt. The paddle is connected to drive means that can cause it to pivot one half-turn synchronously with movement of an article from a vertical position in which its lower part is in the trajectory of the articles and its face that supports the tape faces upstream, and being provided with holding means that temporarily and/or sequentially connect each of its lengthwise faces with the handle formed at the end of adhesive tape to pull this tape and apply its non-adhesive back to said lengthwise face, and, additionally, cooperates with means for cutting the end handle off the tape.
With such a conventional device, when an article comes in contact with the lower end of the vertically disposed paddle and presenting the non-cut handle of the adhesive tape and disposed with its adhesive face facing the moving article, a detector causes the paddle to rotate one half-turn. After the adhesive end of the handle has been applied to the downstream face of the article, upstream tilting of the paddle, during which tilting said paddle assumes a horizontal position above the article before returning to the vertical position just behind the article, guides the wrapping of the handle while bringing and applying the other adhesive end of this handle against the upstream face of the article.
Simultaneously, rotation of the paddle unwinds the adhesive tape and brings the next handle against the other lengthwise face of the paddle, namely against the face which, at the end of the cycle, points upstream.
As soon as the paddle has become vertical once again, the upstream end of the handle applied to the article is cut from the adhesive tape to enable the object to continue its movement.
Such a device is described in European Patent 560,699 in the name of the applicant according to which each end of the paddle has means for holding the adhesive tape, but also cutting means. The holding means are comprised of levers oscillating in the traverse plane and coming together to grip the tape in order to pull the tape and to form a counter-blade cooperating with the cutter blade that cuts the tape.
In the absence of regular maintenance and replacement of the two knives as soon as they become dull, this arrangement causes operating mishaps requiring production downtime. Typical mishaps are insufficient cutting, excessive adhesion of the tape to the clamp, fouling of the cutting means, and tearing off of the applied handle.
Another drawback of this device is that it requires precise adjustments of the timing means for the movements of the clamps and the movements of the knives.
Finally, the arrangement, at each end of the paddle, of the holding and cutting mechanisms with their drive means causes weights and inertias that limit the rotational speed of the paddle and, in any event, do not allow it to function satisfactorily at the high speeds now required, which are on the order of 80 to 100 articles/minute.